Since generally an engine-driven work machine is often used outdoors and an air cleaner connected to an air intake system of the engine is exposed to the atmosphere, a disadvantage can be expected that raindrops running down on an outer wall of a cleaner cover body are sucked into the air cleaner upon receiving an intake negative pressure of the engine.
A conventional arrangement is known in which an air cleaner is provided with a rain cap for preventing rainwater from entering the interior of the air cleaner (see Patent Publication 1 for example).
Further, a conventional general purpose engine air cleaner is known in which a joining tube (air intake tube) is provided on a base plate blocking an opening in a lower face of a cover case, an air cleaner element is fitted to the joining tube, and a packing is disposed between the air cleaner element and the base plate, so that outside air containing dirt does not leak directly toward the engine side without passing through the air cleaner element (see Patent Publication 2 for example).
Furthermore, a conventional arrangement of a general purpose engine is known in which an air cleaner for taking in outside air, cleaning it, and then guiding it to the engine is integrally supported on one side of a cylinder part of the engine by means of a securing member such as a bolt (see Patent Publication 3 for example).    Patent Publication 1: Japanese Utility Model Registration Publication No. 63-11322    Patent Publication 2: Microfilm of Japanese Utility Model Registration Application Laid-open No. 1-78258    Patent Publication 3: Japanese Utility Model Registration Publication No. 59-62263